My mistake entirely - I had not accounted for BLC valid from WP-V3 onward. I installed, activated, saw it did not like the WP-V2.8 environment. It wasn't activated as far as I could see, uninstalled, but damage was done.
Site link: http://www.ardgayanddostrictcommunitycouncil.org.uk
I suspect page.php is not doing what it should do - or worse.
Is this a restore backup situation?
Thank you.